1. Field of the Invention
The present invention relates to a diamond screening apparatus and, more particularly, to a diamond screening apparatus for screening diamond particles which is used to prepare a chemical mechanical polishing conditioner.
2. Description of Related Art
Chemical mechanical polishing (CMP) is a common polishing process in various industries, which can be used to grind the surfaces of various articles, including ceramics, silicon, glass, quartz, or a metal chip, etc. In addition, with the rapid development of integrated circuits, chemical mechanical polishing becomes one of the common techniques for wafer planarization due to its ability to achieve whole planarization.
During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer are removed by contacting the wafer (or the other semiconductor elements) with a polishing pad and using a polishing liquid if necessary, through the chemical reaction and mechanical force. When the polishing pad has been used for a certain period of time, the polishing performance and efficiency are reduced because the debris produced in the polishing process may accumulate on the surface of the polishing pad. Therefore, a conditioner can be used to condition the surface of the polishing pad, such that the surface of the polishing pad is re-roughened and maintained at an optimum condition for polishing. In the process for manufacturing a conditioner, it is necessary to dispose an abrasive layer by mixing abrasive particles and a binding layer on the substrate surface, and to fix the abrasive layer to the surface of the substrate by brazing or sintering methods. During the manufacturing process of the above conditioner, or when the conditioner conditions a polishing pad, the diamond particles on the conditioner may be broken to form risk diamonds, such that the conditioner may become a defective one. Therefore, it is necessary to implement a detection process for ensuring an expected polishing performance in the subsequent steps. It is a known method to use an optical microscope (OM) to perform a visual observation whether a pad conditioner has any risk diamond. When risk diamonds are observed, the positions would be marked by a marked method (such as oil pen) and taken a photograph. Finally, the photos taken before and after the grinding process would be compared by a person.
In the known technology, it discloses an equipment for detecting a defect of a polishing pad conditioner, comprising a working platform, a placement base and an image capture device disposed on the working platform, a display module, and an image processing unit. The image processing unit includes an image recognition module, a data storage device and a comparison module, wherein the data storage device is electrically connected with the image recognition module and the comparison module, and stores a plurality of reference image data. The image recognition module transfers the sample image to a sample image data having the same format as the reference image data. The comparison module executes a comparison of the sample image data and the corresponded reference image data to determine whether any one of the sample image data has any defect. The sample images having defects and without defects would be separately marked and shown in the display module.
In addition, the other known technology, it discloses a detection apparatus and method of chemical mechanical polishing conditioner, comprising: a working platform with a working plane; a placement base disposed on the working plane of the working platform for carrying a chemical mechanical polishing conditioner; an image capture device disposed on the placement base of the working platform, and the image capture device and placement base relatively parallel to the working plane for forming one or a plurality of captured images in different regions of the chemical mechanical polishing conditioner; a display device; an image recognition module connected electrically to the image capture device and the display device; wherein the captured image is performed a color matching the captured images by the image recognition module to determine one or a plurality of risk diamond on the chemical mechanical polishing conditioner, and the coordinate locations of the risk diamonds are outputted to the display device; and a mobile platform used to move the risk diamonds to specified locations which are the coordinate location outputted by the image recognition module.
However, the above detection apparatus is used to perform a detection of risk diamonds on a prepared chemical mechanical polishing conditioner. Even though the risk diamond can be removed by an appropriate removal device, the productivity of the chemical mechanical polishing conditioner cannot still be effectively improved. Thus, there is a demand to develop a screening and detecting apparatus for risk diamonds and a method using the same, wherein the risk diamonds can be removed before a brazing process to avoid producing scratches and breakages caused by the risk diamonds during a chemical mechanical polishing process.